1. Field
Apparatuses consistent with exemplary embodiments relate to apparatuses for recording holograms, and more particularly, to apparatuses for recording holograms at high speed by simultaneously recording a plurality of hogels.
2. Description of the Related Art
Holography is a technology whereby an interference pattern between a signal beam containing a signal and a reference beam is recorded to reproduce the signal as a stereoscopic image. Holography may be used in various fields such as the recording and reproduction of stereoscopic images, the prevention of forgery and the verification of genuine articles, or the recording and reproduction of digital data. In addition, fine interference patterns may be recorded on a flat photosensitive recording film in units of pixels, (or hologram pixels (hogels)), so that a three-dimensional image may be viewed on a two-dimensional plane.
Holograms may be classified as rear projection holograms or reflective holograms. A rear projection micro-hologram is a stereoscopic image formed by light that has been transmitted through a recording film, and a reflective hologram is a stereoscopic image formed by light that has been reflected off a recording film. In particular, a reflective hologram may be used to record/reproduce full-color or full-parallax images and may represent gradation.
Typically, a hologram may be recorded by dividing a beam emitted from a light source into a signal beam and a reference beam, modulating the signal beam, and irradiating the signal beam and the reference beam at the same location on a photosensitive recording film. the signal beam may be modulated by using a spatial light-modulator according to an interference pattern calculated by a computer based on an image that is to be finally reproduced the photosensitive recording film.
To record such holograms at high speed, it is very important to simultaneously record a plurality of hogels that are basic units of holograms. Typically, a method of redundantly installing a plurality of optical elements is used in order to simultaneously record a plurality of hogels. However, this method is likely to increase the manufacturing cost of hologram recording apparatuses and is spatially restrictive.